Applying agricultural chemicals with xanthomones hydrophillic colloids

ABSTRACT

Method of applying agricultural chemicals by forming an admixture of an agricultural chemical, an aqueous carrier therefor, and a Xanthomonas colloid in an amount in the range of 0.02 percent to 2.0 percent by weight of the aqueous component, and applying the agricultural chemical. As a new composition, an agricultural chemical, an aqueous carrier therefor, and from 0.2 percent to 2.0 percent by weight of the aqueous component of a Xanthomonas hydrophilic colloid.

United States Patent 91 Gibsen et al.

[ 1 Feb. 20, 1973 154] APPLYING AGRICULTURAL CHEMICALS WITH XANTHOMONESHYDROPHILLIC COLLOIDS Saddington, both of San Diego,

Calif. t [73] Assignee: Kelco Company, San Diego, Calif. [22] Filed:Jan. 16, 1970 [21] Appl. No.: 4,469

Related U.S. Application Data [63] Continuation of Ser. No. 759,203,Sept. 11, 1968, abandoned, which is a continuation-in-part of Ser. No.392,300, Aug. 26, 1964, abandoned.

3 ,258,326 6/1966 Rabussier ..71/93 3,143,407 8/1964 Mitchell et a1...71/80 3,060,084 10/ 1962 Littler ..71/D1G. 1 3,157,486 11/1964Harrison et a1... ..71/D1G. 1 3,000,790 9/1961 Jeanes et al. ..195/313,271,267 9/1966 Weber et al...... ....l95/3l 3,355,447 11/1967O'Connell ..195/31 FOREIGN PATENTS OR APPLICATIONS 630,023 10/1949 GreatBritain ..7l/DlG. 1

Primary Examiner-Lewis Gotts Assistant Examiner-G. l-lollrahAttorney-Elwood S. Kendrick, Thomas H. Jones and Kendrick and Subkow [57] ABSTRACT Method of applying agricultural chemicals by forming anadmixture of an agricultural chemical, an aqueous carrier therefor, anda Xanthomonas colloid in an amount in the range of 0.02 percent to 2.0percent by weight of the aqueous component, and applying theagricultural chemical. As a new composition, an agricultural chemical,an aqueous carrier therefor, and from 0.2 percent to 2.0 percent byweight of the aqueous component of a Xanthomonas hydrophilic colloid.

7 Claims, No Drawings APPLYING AGRICULTURAL CHEMICALS WITH XANTHOMONESHYDROPHILLIC COLLOIDS This application is a continuation of our priorcopending application Ser. No. 759,203, filed Sept. ll 1968 and nowabandoned, which in turn is a continuation-in-part of our priorapplication Ser. No. 392,300, filed Aug. 26, 1964 and now abandoned.

This invention relates to a new and useful method of applyingagricultural chemicals.

Horticulturalists are regularly concerned with pro tecting orcontrolling the growth of plants. To accomplish such a purpose theyspray coat plants with agricultural chemicals such as pesticides,fungicides, growth modifiers to promote growth of plants, or herbicidesto kill undesired plant life commonly known as weeds. Other agriculturalchemicals are used to kill insects and pests such as flies, mosquitos,mites, ticks, weevils, termites, lice, and nematodes. In the followingand in the appended claims the words agricultural chemicals are intendedto include all of the foregoing.

Agricultural chemicals are commonly applied in water solutions,suspensions or emulsions in treating plant life. Said applications aremade to root, stem, foliage, fruit, or flower depending upon the objectto be accomplished by the particular treatment. To be effective, thetreating materials must remain in contact with the plant life to whichthey are applied. In addition, it is usually very undesirable for thesetreating materials to drift onto neighboring areas. For example, it iscommon to spray such treating materials to the planted areas alonghighways, freeways, and the like. If the active ingredient in the spraydrains from the growth, much of it is wasted and its effectivenessdissipated. At the same time if the spray, for example, is herbicide andit drifts onto neighboring farmland it can destroy valuable crops.Similarly, the effectiveness of agricultural chemicals when applied topests or animals or other objects is increased when the chemicals adhereto the animal or object being treated.

It is an object of our invention to provide a new and useful method ofapplying agricultural chemicals.

It is a further object of our invention to provide a method ofincreasing the adherence of agricultural chemicals to plants, animalsand surfaces treated therewith.

It is still another object of our invention to provide a method ofapplying treating materials to plant life that is capable of confiningthe applied treating materials to plants in a given area.

It is still an additional object of our invention to increase theefficiency of the application of agricultural chemicals.

In accordance with our invention we have surprisingly found that one ormore of the foregoing objectives may be obtained by incorporating arelatively small amount of a Xanthomonas hydrophilic colloid in aqueouscarriers for agricultural chemicals. Suitable amounts of such a colloidfor our purpose are in the range of 0.02 to 2.0 percent by weight of theaqueous component of said carrier. Amounts in the range of 0.1 to 1.0percent of said colloids by weight of the aqueous component of theaforesaid carrier are preferred.

For example, to use our method in applying an agricultural chemical,such as a herbicide, to plant life we may disperse or dissolveXanthomonas campestris hydrophilic colloid in water at a concentrationof onehalf to 1 percent by weight although much lower levels are oftenusable. To this solution or dispersion so produced we may add 1 percentof the soluble dimethylamine salt of 2,4-dichlorophenoxyacetic acid, awell known herbicide. The water soluble Xanthomonas campestrishydrophilic colloid herbicide solution so produced while considerablythicker than water will have a viscosity within the exemplary range of400 to 1,200 centipoises. Such a solution surprisingly is easilypumpable with equipment used in the commercial application ofherbicides.

We find that a particularly effective preparation is attained if theXanthomonas campestris hydrophilic colloid is used at 0.7 percent byweight of the water in the aqueous solution and the herbicide is used ata concentration of about 1 percent by weight. This exemplary mixture hasa number of highly special and very effective properties. In the firstplace it will stick to surfaces of plant life of varying shapes andsizes including trees, shrubs, and vegetables as well as to portionsthereof. Thus, for example, our preparation will adhere to roots, stems,leaves, flowers, and fruit. Additionally, because of the very viscousconsistency of the mixture relatively thick layers are formed on theplant, which serve to maintain a relatively large quantity of water andherbicide at and on the plant surface to be treated. Moreover, the thickadhesive coating serves to retard not only runoff of the herbicidesolution but also evaporation, thereby increasing the effectiveness ofthe herbicidal action.

In the aforementioned example of our invention employing a Xanthomonashydrophilic colloid, we refer to such a colloid produced by thebacterium Xanthomonas campestris. This colloidal material is a polymercontaining mannose, glucose, potassium glucuronate and acetyl radicals.In such a colloid, the potassium portion can be replaced by severalother cations without substantial change in the property of the saidmaterial for my purpose.

The said colloid, which is a high molecular weight, exocellularmaterial, may be prepared by the bacterium Xanthomonas cam pestris, bywhole culture fermentation of a medium containing 2-5 percent commercialglucose, organic nitrogen source, dipotassium hydrogen phosphate andappropriate trace elements. The incubation time is approximately 96hours at 28C., aerobic conditions. In preparing the colloid asaforesaid, it is convenient to use corn steep liquor or distillers drysolubles as an organic nitrogen source. It is expedient to grow theculture in two intermediate stages prior to the final inoculation inorder to encourage vigorous growth of the bacteria. These stages may becarried out in media having a pH of about 7. In a first stage a transferfrom an agar slant to a dilute glu cose broth may be made and thebacteria cultured for 24 hours under vigorous agitation and aeration ata temperature of about 30C. The culture so produced may then be used toinoculate a higher glucose (3 percent) content broth of larger volume ina second intermediate stage. In this stage the reaction may be permittedto continue for 24 hours under the same conditions as the first stage.The culture so acclimated for use with glucose by the aforementionedfirst and second stages is then added to the final glucose medium. Inthe aforesaid method of preparing Xanthomonas campestris hydrophiliccolloid, a loopful of organism from the agar slant is adequate for thefirst stage comprising 200 milliliters of the said glucose media. In thesecond stage the material resulting from the first stage may be usedtogether with 9 times its volume of a 3 percent glucose media. In thefinal stage the material produced in the second stage may be admixedwith 19 times its volume of the final media. A good final media maycontain 3 percent glucose, 0.5 percent distillers dry solubles, 0.5percent dipotassium phosphate, 0.1 percent magnesium sulphate having 7molecules of water of crystallization and water. The reaction in thefinal stage may be satisfactorily carried out for 96 hours at 30C. withvigorous agitation and aeration. The resulting Xanthomonas campestriscolloidal material which we have found to be particularly suitable forour purpose can be recovered by precipitation in methanol of theclarified mixture, i.e., the filtered or centrifuged mixture, from thefermentation. This resulting material may also be designated as apseudoplastic, heteropolysaccharide hydrophilic colloid or gum producedby the bacterium species Xanthomonas campestris.

Additionally, the reaction mixture containing the Xanthomonashydrophilic colloid, as described above, can be dried as by passing thereaction mixture onto a drum dryer and removing the Xanthomonas colloidand any solid impurities present therewith from the drum with a doctorblade. Still further, the Xanthomonas colloid in the reaction mixture,i.e., the fermentation beer, can be treated with an alkali metalhypochlorite as described in US. application Ser. No. 697,034, filedJan. 11, 1968, now US. Pat. No. 3 ,5 I 6,983 to oxidize proteinaceousimpurities followed by precipitation. of the colloid through addition ofa lower alcohol. The description set forth in US. application Ser. No.697,034, now US. Pat. No. 3,516,983 is incorporated herein by reference.

Additional Xanthomonas colloidal material may be prepared by repeatingthe procedure used for producing the Xanthomonas campestris colloidalmaterial described above by substituting known Xanthomonas bacteria ororganisms, i.e., Xanthomonas carotae, Xanthomonas incanae Xanthomonasbegoniae, and Xanthomonas malvacearum, for the bacterium, Xanthomonascampestris. In using Xanthomonas colloidal material produced by theXanthomonas bacteria as aforementioned other than Xanthomonas campestriswe vary the quantity of the Xanthomonas colloid used in our methoddepending upon the particular species. More particularly, we have foundthat when using a Xanthomonas colloid produced by the organism Xanthomonas carotae, we required 1.9 parts of said colloid as asubstitute for each part of a colloid produced by the bacteriumXanthomonas campestris. Similarly, when substituting the colloidproduced by the bacterium Xanthomonas incanae, 1.5 parts were required;when substituting Xanthomonas begoniae, 1.65 parts were required, andwhen substituting Xanthomonas malvacearum, 1.25 parts were required.

In the foregoing example of applying an agricultural chemical we havemade reference to applying a herbicide to plant life. The surprisingeffectiveness of our method for this purpose also pertains to, usingagricultural chemicals in aqueous solutions, suspensions or emulsions assprays for animals, insect control, and the like.

Our method may be used in applying treating materials by both surfaceand airborne equipment.

"It will be noted in using the invention of our method in applyingagricultural chemicals that the solutions, suspensions and/or emulsionsinitially prepared in accordance therewith are relatively viscous asmeasured on a Brookfield viscometer or similar instrument. Surprisingly,however, when subjected to pump pressure and the like they have afluidity approaching a low viscosity material. Further, on leaving theejection nozzles these materials return to a viscous character thatconfines the stream to the area intended to be treated even underadverse conditions. Thus, for example, as the stream of a herbicideutilizing our method strikes plant leaves, stems, etc. it flows readilyfor an instant of time and provides a thorough coating on all sides.However, moments after coating the surfaces involved, the consistencyturns to one of extremely high viscosity which prevents the herbicidefrom running off. The practical significance of our method is thatagricultural chemicals utilizing aqueous carriers can be preparedconveniently, transferred readily, pumped and sprayed easily. Stillfurther, a spray thereof will resist wind drift, coat the intendedsurface thoroughly, maintain said coating tenaciously and thereby makean effective and extensive application of the active ingredients on thedesired surfaces without waste due to draining or damage due to drift tosurrounding areas.

These treating materials to which our invention is applicable are soldas solids in crystal and powder form and as liquids. It will beappreciated by those skilled in the art that in preparing the aqueousadmixture of a water soluble Xanthomonas hydrophilic colloid and atreating material in order to provide a relatively uniform admixture itmay be necessary or desirable to use known stabilizers, sequesteringand/or emulsifying agents in said treating material admixture.

It will be still further appreciated by those skilled in the art thatthere are a wide variety of agricultural chemicals and mixtures thereofand carriers or extenders therefor, to which the instant invention isapplicable. In the following, we set forth examples of chemicals thatmight be used in accordance with our method.

EXAMPLE I: I-IERBICIDES dimethyl-2, 3, 5, 6, tetrachloroterephthalate.

2,2-dichloropropionic acid, sodium salt 2,4,S-trichlorophenoxyaceticacid, salts and esters thereof.

2-(2,4-dichloro phenoxy) propionic acid 2,4-dichlorophenoxyacetic acid,salts and esters thereof EXAMPLE II: FUNGICIDESN-trichloromethylmercapto-4-cyclohexene- 1 ,2-

dicarboximide; tetramethyl thiuram disulfidel,2,3,4,5,6-hexachlorobenzene disodium ethyl bisdithiocarbamate EXAMPLEIII: INSECTICIDES 1 ,2,4,5 ,6,7,8,8-octachloro-3a,4,7 7a-tetrahydro-4,7-methanoindane l ,l 1-trichloro-2,2-bis(p-chlorophenyl)-ethane,

EXAMPLE IV: MlTlCIDES 2-( p-tert-butylphenoxy )-isopropyl p-chlorophenylp-chlorobenzenesulfonate tetraethyl pyrophosphate O ,O-diethylphosphorodithioate 2-chloroethyl s-(p-chlorophenylthiomethyl) EXAMPLE V:GROWTH CONTROL AGENTS tributyl 2,4-dichlorobenylphosphonium chloride 2-(3-indole )butyric acid 1 ,2-dihydro-pyridazine-3,6-dione To furtherdemonstrate the surprising nature of our invention in terms of reducingdrainage from'a treated surface, various aqueous solutions wereprepared, each of which was thickened to a viscosity of 1,000 cps: cpsby the addition of a particular thickener and also contained 2 percentby weight of the herbicidally active dimethyl amine salt of2,4-dichlorophenoxyacetic acid. Each of the thickened test solutions wastested by placing 50.0 grams of the solution on a flat, somewhat waxysurface inclined approximately 30 from the horizontal plane. Thesolution under test was then allowed to drain for 30 minutes and theloss of solution from the surface was determined. The results of thesetests are set forth in the following Table I in which the thickenerpresent in the test solution is set forth in column 1, the percent byweight of solution remaining on the inclined surface at the end of thetest (percent retention) is set forth in column 2, and the averagepercent retention for the two tests is set forth in column 3.

As shown by the above data, the percent retention of the test solutionscontaining a Xanthomonas colloid was almost three times that of thesolutions containing gum tragacanth and more than ten times that of thesolutions containing hydroxyethylcellulose. The fact that the testsolutions containing a Xanthomonas hydrophilic colloid were so resistantto drainage is, of course, of great significance in the treatment ofplants or animals with an agricultural chemical since the effectivenessof the agricultural chemical is increased in direct proportion to itspercent retention of the treated object.

In still further tests aqueous solutions containing various thickenerswere prepared at viscosities of 500 cps and 1,000 cps. Each of the testsolutions was then pumped through a gear pump at close to the maximumflow rate obtainable. Both the flow rate and the pumping pressure weremeasured for each of the solutions under test. The results are shown inthe following Table II in which the thickener employed is set forth incolumn 1, the viscosity of the test solution in centipoises is set forthin column 2, the pumping pressure is set forth in column 3 and the flowrate in gallons per minute is set forth in Column 4.

As shown in the above table, the test solutions containing XanthomonasHydrophilic Colloid exhibited greater flow rates at lower pumpingpressures than the solutions containing sodium alginate orl-lydroxyethyl Cellulose. Moreover, the 1,000 cps test solutioncontaining Xanthomonas Hydrophilic Colloid was more easily pumped thanthe 500 cps test solutions containing sodium alginate or hydroxyethylcellulose. This, of course, is of great significance in the use of ourinvention in applying an agricultural chemical since it permits thepumping and spraying of a very viscous aqueous solution or suspension ofthe agricultural chemical in a manner which is impossible when usingconventional thickeners such as alginates or hydroxyethyl cellulose.

We claim:

1. In a viscous liquid composition for agricultural spraying, having aviscosity within the range of 400 to 1,200 centipoises and showing adecrease in viscosity when subjected to shear, thereby improving itsability to be pumped and to be sprayed, which composition compriseswater and an effective amount of a chemical selected from the class ofpesticides and growth modifiers, the improvement consisting essentiallyof having incorporated therein from 0.02 to 2.0 percent by weight ofsaid water of Xanthomonas hydrophilic colloid.

2. The composition of claim 1 wherein said colloid is Xanthomonascampestris hydrophilic colloid.

3. The composition of claim 2 wherein the amount of said colloid is 0.1to 1.0 percent.

4. The agricultural growth modifier composition of claim 1 having aviscosity of about 1,000 centipoises consisting of water, Xanthomonascampestris hydrophilic colloid, and 2 percent by weight of dimethylaminesalt of 2,4-dichlorophenoxy acetic acid.

5. A method of retarding the runoff and evaporation of agriculturalpesticide and growth modifier solutions applied to surfaces, whichmethod comprises spraying a viscous liquid composition, having aviscosity within 6. The method of claim wherein said colloid is therange of 400 to 1200 centipoises, containing an ef- Xamhomonascamp'estris h d hili ll id fectiye arnount of a chemical selected fromthe class 7. The method of claim 6 wherein the amount of said consistingof pesticides and growth modifiers, and a COllOld is 0.1 to 1.0 percent.

water solution of Xanthomonas hydrophilic colloid, the 5 amount of saidcolloid being from 0.02 to 2.0 percent.

1. In a viscous liquid composition for agricultural spraying, having aviscosity within the range of 400 to 1,200 ceNtipoises and showing adecrease in viscosity when subjected to shear, thereby improving itsability to be pumped and to be sprayed, which composition compriseswater and an effective amount of a chemical selected from the class ofpesticides and growth modifiers, the improvement consisting essentiallyof having incorporated therein from 0.02 to 2.0 percent by weight ofsaid water of Xanthomonas hydrophilic colloid.
 2. The composition ofclaim 1 wherein said colloid is Xanthomonas campestris hydrophiliccolloid.
 3. The composition of claim 2 wherein the amount of saidcolloid is 0.1 to 1.0 percent.
 4. The agricultural growth modifiercomposition of claim 1 having a viscosity of about 1,000 centipoisesconsisting of water, Xanthomonas campestris hydrophilic colloid, and 2percent by weight of dimethylamine salt of 2,4-dichlorophenoxy aceticacid.
 5. A method of retarding the runoff and evaporation ofagricultural pesticide and growth modifier solutions applied tosurfaces, which method comprises spraying a viscous liquid composition,having a viscosity within the range of 400 to 1200 centipoises,containing an effective amount of a chemical selected from the classconsisting of pesticides and growth modifiers, and a water solution ofXanthomonas hydrophilic colloid, the amount of said colloid being from0.02 to 2.0 percent.
 6. The method of claim 5 wherein said colloid isXanthomonas campestris hydrophilic colloid.